1.1 POJA-L717. Plasma cells (spleen, mouse

1.1  POJA-L717

Title: Plasma cells (spleen, mouse)   
 
Description: Electron microscopy. 
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The mature plasma cell shows an excentric nucleus with a characteristic chunky distribution of heterochromatin along the inner nuclear membrane  (“spoke-wheel” effect in light microscopy). Juxtanuclearly an elaborate Golgi area (2) with secretion vacuoles is localized (cytocentrum/centrosome).
The cytoplasma is packed with long dilated profiles of rough endoplasmic reticulum (RER) filled with electron-grey material (1) confirming the production of antibodies. The amount of RER and the degree of dilation are indicative for the activity of the plasma cell. In light microscopy this results in the deep basophilia of the cytoplasm and the light-stained centrosome (so-called nuclear “hof”).

Background: A pluripotent hematopoietic stem cell gives rise to a common lymphoid progenitor cell. The latter divides to produce two types of lymphoid stem cells. One type migrates to the thymus, proliferates and differentiates into T lymphocytes. The other type remains in the bone marrow or settles in the spleen, lymph nodes where it proliferates into lymphoblasts that in turn divide and eventually result in immunocompetent B lymphocytes. Dependent on the appropriate stimulation B lymphocytes can be activated to divide and differentiate via plasmablasts into antibody-secreting plasma cells (plasmacytes).
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 Keywords/Mesh: blood, bone marrow, plasma cell, histology,  electron microscopy, POJA collection